How do I count rows in one table based on values in another table using DAX

Question

What I am trying to accomplish is to calculate the number of times that value appears in Table2 as a new column in Table1. How do I count rows in one table based on values in another table using DAX

Answer 1

If the tables are related, this is very simple, you can see the below-given suggestion:

Number of Table2 rows = COUNTROWS(RELATEDTABLE(Table2))

Then you can add a Calculated Column to Table1 which counts the times each item appears in Table2:

Number of Table 2 rows: COUNTROWS(RELATEDTABALE(Table2))

If the tables are not related, you can use CALCULATE and FILTER:

Number of Table2 rows =
CALCULATE(
    COUNTROWS(Table2),
    FILTER(
        Table2,
        Table2[Column1] = Table1[Column1]
    )
)